The present invention relates to electronic devices and more particularly to a touch screen input technique for allowing a user input to an electronic device having a touch screen.
Advances in technology have resulted in smaller and more sophisticated electronic devices becoming available. These devices, such as portable communication devices, allow a user wireless access to communication networks, thereby enabling both Internet access and two-way e-mail communication.
As the size of these communication devices decreases and as the number of functions increase, it has become increasingly important for a user to be able to enter commands and information into the communication device in an efficient manner. With a reduction in size of the device, a keypad input device must also be reduced in size, thereby decreasing the efficiency with which information can be input by reducing the number and size of the keys. Furthermore, with a reduction in size of the device, the display size must also be reduced. Still furthermore, the use of a mouse with such devices is usually not possible since a mouse requires a flat clean surface to be properly used.
The use of a touch screen input device that serves both as a display and as an input device for the communication device allows a larger display in that a large keypad is no longer required since many of the functions have been taken over by the use of the display screen as an input device. A user enters information and data by touching the display screen at specific points.
U.S. Pat. No. 4,700,022 to Salvador et al. is directed to a method an apparatus for determining the coordinates of a contact point on a resistive type semi-analog sensitive surface. The coordinates are of a zone of contact of a conductive object, such as a finger, on a sensitive surface consisting of an insulating support having a grate formed by two terminals between which a certain number of emitting resistant strips are connected in parallel and having detecting conductive strips placed between the resistant strips. This patent merely discloses one of many techniques for determining the location of the zone of contact on a touch sensitive screen.
U.S. Pat. No. 5,119,079 to Hube et al. is directed to a touch screen user interface with expanding touch locations for a reprographic machine. The interface allows the expansion of the area for selection on the touch screen so as to improve the accuracy of selection thereof.
U.S. Pat. No. 5,545,857 to Lee et al. is directed to a remote control device having a touch screen allowing a user input via the touch screen.
While the three above-noted patents each disclose the use of a touch screen for inputting purposes, none of these patents teach or suggest a touch screen arrangement in which both the location and the time duration of a finger or other object contacting the touch screen are detected, the detected time duration being quantized into two or more values, each value corresponding to a specific input state.